JP2006328980A - Ignition control device for internal combustion engine with exhaust turbocharger - Google Patents

Abstract

To improve turbo response when accelerating from a low engine speed.
An ignition control device for an internal combustion engine with an exhaust turbo supercharger that controls the ignition operation of each of a plurality of spark plugs (first and second spark plugs 70A, 70B) provided per cylinder. In 50A, there is provided an operating ignition number control means 50a for reducing the number of ignition plugs for performing the ignition operation in each of the ignition plugs (first and second ignition plugs 70A, 70B) at the time of acceleration with a low engine speed. thing. For example, the operating ignition number control means 50a ignites only the first spark plug 70A among the first and second spark plugs 70A, 70B.
[Selection] Figure 1

Description

  The present invention relates to an ignition control device for an internal combustion engine with an exhaust turbocharger in which a plurality of ignition plugs are provided per cylinder.

  2. Description of the Related Art Conventionally, there is an internal combustion engine that includes a plurality of spark plugs in one cylinder and changes the number of spark plugs per cylinder that is ignited according to the engine operating state.

  For example, as this type of internal combustion engine, one having two spark plugs per cylinder is disclosed in Patent Document 1 below. In this internal combustion engine, two-point ignition is performed with two spark plugs when the operation region is low load, while one-point ignition is performed only with the ignition plug on the side wall side of the combustion chamber when the operation region is medium load. If the load is high, one-point ignition is performed only with the spark plug at the center of the combustion chamber. As described above, in the internal combustion engine disclosed in Patent Document 1, by changing the number and position of the ignition plugs that perform the ignition operation according to the operation region, combustion stabilization and NOx in each operation region are changed. To reduce the amount of emissions.

  Patent Document 2 below also discloses an internal combustion engine having two spark plugs per cylinder. In the internal combustion engine disclosed in Patent Document 2, one-point ignition is performed only with a spark plug at the center of the combustion chamber during normal operation, while two-point ignition is performed with two spark plugs during acceleration or high-load operation. By doing so, knocking at the time of acceleration or the like is suppressed.

  As described above, by providing a plurality of spark plugs in one cylinder and controlling the number of spark plugs to be ignited according to the engine operating state, various effects as described above can be obtained. .

JP-A-2-286880 JP 2004-232478 A

  By the way, in an internal combustion engine having a plurality of spark plugs in one cylinder, an exhaust turbocharger is provided to further improve torque while stabilizing combustion and reducing NOx emissions. May be.

  Here, the exhaust turbocharger generally has a low turbine speed and a slow turbo response at a low engine speed before interception where a predetermined supercharging pressure is applied. For this reason, even if an attempt is made to accelerate the vehicle from the low rotation speed, the torque does not rise quickly due to the slowness of the turbo response, so a time difference occurs until the desired acceleration is obtained.

  Accordingly, the present invention provides an ignition control device for an internal combustion engine with an exhaust turbocharger that improves the disadvantages of the conventional example and can improve the turbo response when accelerating from a low engine speed. And its purpose.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided an ignition control apparatus for an internal combustion engine with an exhaust turbocharger that controls the ignition operation of each of a plurality of spark plugs provided per cylinder. There is provided an operating ignition number control means for reducing the number of ignition plugs that perform the ignition operation in each ignition plug during acceleration in a low number state.

  The ignition control apparatus according to claim 1 reduces the number of ignition plugs that perform the ignition operation, that is, increases the combustion temperature in the combustion chamber as compared with the case of multipoint ignition by reducing the number of operating ignitions. This increases the temperature of the exhaust gas before the turbine. As a result, the turbine speed increases and the intake air amount increases, so that the shaft torque can be increased as compared with the case of multipoint ignition, and the response of the exhaust turbocharger during acceleration with a low engine speed Can be improved.

  Here, the operating ignition number control means, as in the second aspect of the invention, does not apply to the ignition plug disposed on the center side of the combustion chamber when reducing the number of ignition plugs for performing the ignition operation. It is preferable that the ignition operation is performed. As a result, for example, the combustion temperature in the combustion chamber can be further increased as compared with the ignition plug disposed on the side wall side of the combustion chamber, so that the responsiveness of the exhaust turbocharger can be improved more effectively. Can be made.

  According to the ignition control apparatus for an internal combustion engine with an exhaust turbocharger according to the present invention, the temperature of exhaust gas before the turbine is increased by reducing the number of operating ignitions at the time of acceleration when the engine speed is low. Since the turbocharging effect of the turbocharger can be enhanced, the turbo response when accelerating at a low engine speed is improved as compared with the case of multipoint ignition. For this reason, the driver can obtain the desired acceleration feeling during the transition period up to the intercept point where the exhaust turbocharger can obtain a predetermined boost pressure, and the accelerator pedal is depressed more than necessary. Since it is not necessary, the deterioration of the fuel consumption rate can be suppressed.

  Embodiments of an ignition control apparatus for an internal combustion engine with an exhaust turbocharger according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

  A first embodiment of an ignition control apparatus for an internal combustion engine with an exhaust turbocharger according to the present invention will be described with reference to FIGS.

  First, an example of an internal combustion engine to which the ignition control device of the first embodiment is applied will be described with reference to FIG. Reference numeral 10 in FIG. 1 indicates the internal combustion engine of the first embodiment. Although only one cylinder is shown here, the present invention is applicable to a multi-cylinder internal combustion engine regardless of the type such as in-line or V-type.

  The internal combustion engine 10 of the first embodiment includes a cylinder head 12, a cylinder block 13, and a piston 14 that form a combustion chamber 11, as shown in FIG. Here, the cylinder head 12 and the cylinder block 13 are fastened with bolts or the like via the head gasket 15 shown in FIG. 1, and the recess 12a on the lower surface of the cylinder head 12 and the cylinder bore 13a of the cylinder block 13 formed thereby. In the space, the piston 14 is disposed so as to be reciprocally movable. The combustion chamber 11 described above is constituted by a space surrounded by the wall surface of the recess 12 a of the cylinder head 12, the wall surface of the cylinder bore 13 a, and the top surface 14 a of the piston 14.

  Here, in the internal combustion engine 10, an intake passage 20 that guides air from outside into the combustion chamber 11 and an exhaust passage 30 through which the exhaust gas discharged from the combustion chamber 11 flows are provided. An exhaust turbocharger 40 that forcibly supplies a large amount of air into the combustion chamber 11 is arranged between the exhaust passage 20 and the exhaust passage 30.

  The exhaust turbocharger 40 includes a compressor 42 in a compressor housing 41 disposed on the intake path 20, and a turbine in a turbine housing 43 disposed on the exhaust path 30 and rotating on the same axis as the compressor 42. 44, the compressor 44 is rotated by rotating the turbine 44 at high speed with the exhaust gas flowing into the turbine housing 43, and a large amount of air is sent from the outside to the combustion chamber 11 side due to the supercharging effect. .

  First, the intake path 20 of the first embodiment will be described in detail.

  The intake passage 20 is roughly divided into a first intake passage 21 for sucking in air from the outside, and a second intake air connected to the first intake passage 21 via a compressor housing 41 of the exhaust turbocharger 40. A passage 22 and an intake port 23 of the cylinder head 12 for supplying air from outside through the second intake passage 22 and supplying the air into the combustion chamber 11 are provided.

  For this reason, air from the outside flows into the intake port 23 through the first and second intake passages 21 and 22 and is sucked into the combustion chamber 11 from the intake port 23. On the other hand, when there is a supercharging effect of the exhaust turbocharger 40, the air in the first intake passage 21 is supercharged by the compressor 42 and sent to the second intake passage 22, and a large amount of the air is taken in the intake port. The fuel is supplied into the combustion chamber 11 through 23.

Here, on the first intake passage 21 constituting the intake passage 20, an air cleaner 24 for removing foreign matters such as dust from the intake air and an external intake air amount Ga _out are detected in order from the outside. An air flow meter 25 is provided. The detection signal of the air flow meter 25 is sent to an electronic control unit (ECU) 50 which is a control means of the internal combustion engine 10, and the ECU 50 detects the intake air amount Ga _out from the outside.

  Further, a throttle valve 26 for adjusting the intake air amount Ga sucked into the combustion chamber 11 is provided on the second intake passage 22 constituting the intake passage 20. The throttle valve 26 is driven to open and close by a throttle valve actuator 27 shown in FIG. 1 for which a control command for the valve opening angle is given by the ECU 50, so that a desired intake air amount Ga corresponding to the operating state of the internal combustion engine 10 is supplied. Intake into the combustion chamber 11.

  One end of the intake port 23 constituting the intake path 20 opens into the combustion chamber 11, and an intake valve 28 that can open and close the opening is disposed at the opening portion. For this reason, air is sucked into the combustion chamber 11 from the intake port 23 by opening the intake valve 28, while the inflow of air into the combustion chamber 11 is blocked by closing the intake valve 28. Is done.

  The number of openings into the combustion chamber 11 in the intake port 23 may be one or more, and an intake valve 28 is provided for each opening. In the first embodiment, as shown in FIG. 2, there are two openings of the intake port 23, and an intake valve 28 is provided in each of them. Further, when a so-called variable valve mechanism capable of appropriately adjusting the opening / closing timing and the lift amount of the intake valve 28 according to operating conditions is provided, the operation of the variable valve mechanism is controlled by the ECU 50 described above.

  Next, the exhaust path 30 of the first embodiment will be described in detail.

  The exhaust path 30 is roughly divided into an exhaust port 31 of the cylinder head 12 into which the exhaust gas after combustion flows from an opening between the combustion chamber 11 and the exhaust gas after combustion flows through the exhaust port 31. The first exhaust passage 32, the second exhaust passage 33 connected to the first exhaust passage 32 via the turbine housing 43 of the exhaust turbocharger 40, and the exhaust gas that has passed through the second exhaust passage 33. And a catalytic device 34 for purifying harmful components.

  Therefore, the exhaust gas after combustion flows into the catalyst device 34 through the exhaust port 31 and the first and second exhaust passages 32 and 33, and harmful components are purified in the catalyst device 34. On the other hand, the exhaust gas flowing through the exhaust port 31 and the first exhaust passage 32 reaches a predetermined pressure (that is, reaches a predetermined supercharging pressure at which the supercharging effect of the exhaust turbocharger 40 is obtained). In this case, since the exhaust gas rotates the turbine 44 at a high speed, the air in the first intake passage 21 is supercharged by the rotation of the compressor 42 on the same shaft, and a large amount of air is supplied into the combustion chamber 11. .

  An exhaust valve 35 that can open and close an opening between the exhaust port 31 and the combustion chamber 11 is disposed in the exhaust port 31 constituting the exhaust path 30. Therefore, the exhaust gas is discharged from the combustion chamber 11 to the exhaust port 31 by opening the exhaust valve 35, and the exhaust of the in-cylinder gas to the exhaust port 31 is blocked by closing the exhaust valve 35. Is done.

  The number of openings into the combustion chamber 11 in the exhaust port 31 may be one or plural, and the exhaust valve 35 described above is provided for each opening. In the first embodiment, as shown in FIG. 2, there are two openings of the exhaust port 31, and an exhaust valve 35 is provided in each of them. Further, when a so-called variable valve mechanism capable of appropriately adjusting the opening / closing timing and the lift amount of the exhaust valve 35 according to operating conditions or the like is provided, the operation of the variable valve mechanism is controlled by the ECU 50 described above.

  Here, as the internal combustion engine 10 of the first embodiment, a so-called in-cylinder direct injection internal combustion engine in which fuel is directly injected into the combustion chamber 11 and mixed with intake air in the combustion chamber 11 is exemplified. For this reason, the cylinder head 12 of the first embodiment is provided with a fuel injection device 60 that directly injects fuel into the combustion chamber 11 based on a command from the ECU 50.

  The mixture of fuel and air is ignited by the ignition operation of the first and second spark plugs 70A and 70B shown in FIG. In the first embodiment, as shown in FIG. 2, the first spark plug 70 </ b> A is disposed substantially at the center of the combustion chamber 11, while the side wall surface side (here, the side wall surface side) of the combustion chamber 11. Between the intake valve 28 and an exhaust valve 35 described later). The first and second spark plugs 70A and 70B are controlled by an ignition control device 50A which is one of the control functions of the ECU 50.

  By the way, in order to obtain a high shaft torque due to the supercharging effect of the exhaust turbo supercharger 40, it is necessary to increase the supercharging pressure and increase the turbine speed to increase the intake air amount Ga. However, in a state where the engine speed Ne is low (before the interception of the exhaust turbocharger 40), the flow rate of the exhaust gas flowing into the turbine housing 43 is small, and the temperature of the exhaust gas is also low. Is low, and the intake air amount Ga cannot be increased. For this reason, even if an attempt is made to accelerate the vehicle, the rise of the axial torque is slow until the intercept point where a predetermined supercharging pressure is applied that can obtain the supercharging effect of the exhaust turbocharger 40, and the driver desires I can't get a feeling of acceleration like this. At this time, in order to obtain the desired acceleration feeling, the driver often further depresses the accelerator pedal, so that the fuel consumption rate deteriorates in the transition period from the low engine speed Ne to the intercept point.

  In order to eliminate such inconvenience, the turbine rotational speed may be increased by increasing the flow rate of the exhaust gas flowing into the turbine housing 43 or increasing the temperature of the exhaust gas. However, the flow rate of the exhaust gas depends on the intake air amount Ga and is difficult to increase easily. On the other hand, the temperature of the exhaust gas can be raised by increasing the combustion temperature in the combustion chamber 11.

  Here, when the engine speed Ne is low, the temperature in the combustion chamber 11 is lower than when the engine speed is high. Therefore, the number of operating ignitions to the air-fuel mixture (the number of ignition plugs that perform the ignition operation) is reduced at that time. Thus, the combustion temperature can be raised, whereby the temperature of the exhaust gas flowing into the turbine housing 43 can be raised. FIG. 3A shows the result of measuring the pre-turbine exhaust temperature (temperature of the exhaust gas flowing into the turbine housing 43) for each engine speed Ne during full load operation in the case of one-point ignition and two-point ignition. Is shown. As is clear from FIG. 3-1, in the engine speed Ne before interception, the exhaust temperature before the turbine at the same engine speed Ne is higher in the case of one-point ignition than in the case of two-point ignition. It becomes high and it turns out that the combustion temperature in the combustion chamber 11 is rising.

  As the pre-turbine exhaust temperature rises, the turbine rotational speed at the same engine rotational speed Ne increases as shown in FIG. 3-2. As a result, the intake air amount Ga increases. As shown, the shaft torque at the same engine speed Ne can be increased.

  That is, since the exhaust temperature before the turbine is increased by reducing the number of operating ignitions per cylinder in a state where the engine speed Ne is low, the turbo pressure is increased in the transition period up to the intercept point and the turbo response is improved. .

  Therefore, in the first embodiment, the ignition control device 50A is provided with the operating ignition number control means 50a for reducing the number of ignition plugs that are ignited from the plurality of ignition plugs at the time of acceleration when the engine speed Ne is low. .

  Specifically, in the first embodiment, since two spark plugs (first and second spark plugs 70A and 70B) are provided in one cylinder, the operation ignition number control means 50a of the first embodiment is One-point ignition is performed only with one of the first and second spark plugs 70A and 70B at the time of acceleration when the engine speed Ne is low.

  Here, the combustion temperature in the combustion chamber 11 can be raised as compared with the case where two-point ignition is performed regardless of which one of the first and second spark plugs 70A and 70B is used for one-point ignition. However, even with the same one-point ignition, it is possible to propagate the flame evenly by igniting the central side rather than the side wall side of the combustion chamber 11, so that more air-fuel mixture is burned and the combustion temperature becomes higher. . For this reason, the operating ignition number control means 50a of the first embodiment is set so that one-point ignition is performed by the first ignition plug 70A disposed in the approximate center of the combustion chamber 11.

  By the way, the operating ignition number control means 50a of the first embodiment uses the information on the engine speed Ne and the acceleration request as a trigger when performing such reduction control of the operating ignition number.

  First, the engine speed Ne is calculated based on the detection signal of the crank angle sensor 81 shown in FIG. The operating ignition speed control means 50a of the first embodiment determines whether or not the engine speed Ne is lower than a predetermined speed. If the engine speed Ne is lower than the predetermined speed, the operating ignition speed is determined. The engine speed Ne is determined to be in a low engine speed Ne state to be controlled.

  For example, the engine speed Ne corresponding to the intercept point of the exhaust turbocharger 40 is set as the predetermined engine speed. Here, since the intercept point varies depending on the specifications of the exhaust turbocharger 40, a predetermined rotational speed, that is, a threshold value is determined in accordance with each exhaust turbocharger 40.

  Subsequently, the acceleration request information can be obtained from information such as the opening angle of the throttle valve 26 and the accelerator opening. The operation ignition number control means 50a of the first embodiment determines whether or not it is greater than or equal to a predetermined threshold using at least one of the information such as the valve opening angle. It is configured so that it is determined that the acceleration is requested when the number reduction control is to be performed.

  For example, if information on the valve opening angle of the throttle valve 26 is used, the operation ignition number control means 50a according to the first embodiment uses the valve opening angle command information sent from the ECU 50 to the throttle valve actuator 27. Acceleration may be determined when the angle is greater than or equal to a predetermined angle (threshold), and acceleration occurs when the amount of change in the valve opening angle in the valve opening direction is greater than or equal to a predetermined amount of change (threshold). You may judge it as time.

  Further, if the information on the accelerator opening is used, the operating ignition number control means 50a of the first embodiment determines that the accelerator opening is a predetermined opening (threshold) based on the detection signal of the accelerator opening sensor 82. When it is above, it may be determined that the vehicle is accelerating, and when the amount of change in the accelerator opening is equal to or greater than a predetermined amount of change (threshold), it may be determined that the vehicle is accelerating.

  Here, regardless of which of these is used to determine whether or not the vehicle is accelerating, the threshold value differs for each internal combustion engine, and further for each vehicle on which the internal combustion engine is mounted. Set accordingly.

  On the other hand, under operating conditions other than during acceleration when the engine speed Ne is low, the operating ignition number may be changed according to the engine operating state such as the engine speed Ne and the engine load factor Kl. The engine load factor Kl is a value indicating the current load ratio with respect to the maximum engine load. For example, the valve opening angle of the throttle valve 26 (that is, a value corresponding to the intake air amount Ga into the combustion chamber 11) and the engine speed. It is calculated based on the number Ne. For example, the operating ignition number control means 50a of the first embodiment performs one-point ignition and two-point ignition depending on the engine operating state so as to stabilize combustion, reduce NOx emission, etc., under such operating conditions. Switch appropriately.

  The operating ignition number control means 50a of the first embodiment determines whether or not the control of reducing the number of operating ignitions is necessary for improving the turbo response depending on whether or not the above-mentioned operating conditions during acceleration when the engine speed Ne is low. In the first embodiment, the determination is made using a prepared ignition number switching map shown in FIG.

  The operating ignition speed switching map shown in FIG. 4 is map data indicating the operating ignition speed corresponding to the required torque of the internal combustion engine 10 for each engine speed Ne, and the engine speed before the interception of the exhaust turbocharger 40. A region where one-point ignition is performed when the required torque in the vicinity of full load operation is obtained at the engine speed Ne and the other engine operating conditions Ne and other operating conditions (idle speed and stoichiometric combustion) Or a region in which two-point ignition is performed at the time of partial load operation or the like in lean combustion).

  Here, in this operating ignition number switching map, the time when the required torque in the vicinity of the full load operation is obtained is regarded as an acceleration request, and it is determined that the vehicle is accelerating. Even in this case, whether or not the required torque is near the full load operation can be determined from information such as the opening angle of the throttle valve 26 and the accelerator opening. That is, the required torque of the internal combustion engine 10 is a value calculated from the engine rotational speed Ne, the accelerator opening, etc., and the opening angle of the throttle valve 26 and the accelerator opening at the engine rotational speed Ne before interception are a predetermined threshold value. If it is above, it can be determined that it is the required torque in the vicinity of full load operation, so it can be determined whether or not it is during acceleration by determining whether or not it is the required torque in the vicinity of full load operation. it can.

  For this reason, the operating ignition speed control means 50a of the first embodiment determines whether the engine speed Ne and the throttle valve 26 are open as described above as to whether or not the operating condition is during acceleration when the engine speed Ne is low. The determination may be made from the valve angle or the accelerator opening, or from the engine speed Ne and the required torque. When the determination is made using the latter parameter, the required torque has already been calculated by the ECU 50 in order to perform combustion control and the like, and it is preferable to read and use the calculation result in order to increase the calculation processing speed.

  The increase / decrease control of the number of operating ignitions using the operating ignition number switching map shown in FIG. 4 will be described with reference to the flowchart of FIG.

First, the ignition control device 50A of the first embodiment, by the operation ignition speed control unit 50a, whether the engine speed Ne is lower than the rotation speed Ne _ip interception points of the exhaust turbocharger 40 Is determined from the detection signal of the crank angle sensor 81 (step ST1).

Here, if the low rotation than the rotation speed Ne _ip the engine speed Ne, the operating ignition speed control unit 50a reads the required torque at that time (step ST2), the request torque and the engine speed The operation ignition number is determined by comparing Ne with the operation ignition number switching map (step ST3).

  Then, in step ST3, it is determined that it is a one-point ignition region (that is, the required engine speed Ne near the full load operation is obtained at the engine speed Ne before the interception of the exhaust turbocharger 40). In this case, the operating ignition number control means 50a sends an ignition command only to the first spark plug 70A disposed substantially at the center of the combustion chamber 11, and causes the ignition operation to be executed only from the first spark plug 70A. (Step ST4). The operating ignition number control means 50a thereafter returns to step ST1 and monitors the engine speed Ne.

  By igniting the air-fuel mixture with only the first spark plug 70A in this way, the combustion temperature in the combustion chamber 11 becomes higher than in the case of two-point ignition, so that the exhaust gas flowing into the turbine housing 43 The temperature also increases. Since the turbine rotational speed is higher than that in the case of two-point ignition, the intake air amount Ga into the combustion chamber 11 can be increased, and operation with higher shaft torque than in the two-point ignition becomes possible. . Therefore, by performing the reduction control of the number of operating ignitions in this way, when there is an acceleration request in a state where the engine speed Ne is low as before the interception of the exhaust turbocharger 40, the responsiveness to the acceleration request is increased. Can be improved.

On the other hand, when the engine speed Ne in step ST1 is determined to be the rotation speed Ne _ip or more intercept point of the exhaust turbocharger 40, or a region of the two-point ignition in the step ST3 (i.e., the exhaust If it is determined that the engine speed Ne before interception of the turbocharger 40 is idle speed, partial load operation in stoichiometric combustion or lean combustion, etc.), the operation ignition number control means 50a Then, an ignition command is sent to the first and second spark plugs 70A and 70B, and an ignition operation is executed from the first and second spark plugs 70A and 70B (step ST5). Even in such a case, as described above, one-point ignition may be performed according to the engine operating state. The operating ignition number control means 50a then returns to step ST1 and monitors the engine speed Ne.

  As described above, according to the ignition control device 50A of the first embodiment, the exhaust turbocharger is reduced by reducing the number of operating ignitions at the time of acceleration before the interception of the exhaust turbocharger 40 having a low engine speed Ne. The turbo response in the transition period up to the intercept point at which 40 can obtain a predetermined supercharging pressure can be improved. For this reason, in the transition period, the driver can obtain a desired acceleration feeling, and since the accelerator pedal does not have to be depressed more than necessary, the deterioration of the fuel consumption rate can be suppressed.

  Note that the internal combustion engine 10 to which the ignition control device 50A of the first embodiment is applied is not limited to the direct injection type internal combustion engine as described above, but fuel is injected into the intake port 23 and the inside of the combustion chamber 11 is injected. And may be mixed with the intake air. In such a case, the fuel injection device 60 is disposed on the cylinder head 12 so that fuel can be injected into the intake port 23.

  Next, a second embodiment of the ignition control apparatus for an internal combustion engine with an exhaust turbocharger according to the present invention will be described with reference to FIG.

  In the above-described first embodiment, the internal combustion engine 10 in which two spark plugs (first and second spark plugs 70A and 70B) are provided per cylinder is illustrated. However, the ignition control device according to the first embodiment is illustrated. 50A can be applied even if three or more spark plugs are provided per cylinder.

  Therefore, in the second embodiment, an ignition control device 50A for the internal combustion engine 10 in which three ignition plugs are provided in one cylinder will be exemplified.

  As shown in FIG. 6, the internal combustion engine 10 according to the second embodiment has a first spark plug 70A on the side wall surface side of the combustion chamber 11 opposite to the second spark plug 70B, as shown in FIG. Three spark plugs 70C are added.

  Also in the internal combustion engine 10 having such a configuration, the operation ignition number control means 50a of the ignition control device 50A of the second embodiment executes control for reducing the operation ignition number at the time of acceleration when the engine speed Ne is low.

  Here, since the one-point ignition can raise the combustion temperature in the combustion chamber 11 rather than the three-point ignition than the three-point ignition, the operating ignition number control means 50a of the second embodiment is When accelerating at the engine speed Ne before intercepting the exhaust turbocharger 40, the number of operating ignitions is reduced to the minimum one-point ignition.

  However, even when reduction control of the number of operating ignitions is required, for example, it is sometimes preferable to perform multipoint ignition rather than single point ignition in order to obtain a desired emission performance.

  Therefore, the operation ignition number control means 50a of the second embodiment normally reduces the operation ignition number to one point ignition when accelerating at the engine speed Ne before intercepting the exhaust turbocharger 40, for example, not shown. When deterioration of emission performance is detected from an exhaust gas sensor or the like, the number of operating ignitions is reduced to two-point ignition. Note that, when it is preferable to perform multipoint ignition not only due to such deterioration in emission performance but also due to various factors depending on the operating state, the operating ignition number control means 50a is configured so as to suppress the decrease to two-point ignition.

  As a result, the ignition control device 50A of the second embodiment can improve the turbo response in the transition period up to the intercept point as in the first embodiment, and is preferable for the deterioration of the emission performance according to the operating state. No phenomenon can be avoided.

  Incidentally, even when the number of operating ignitions is reduced as in the second embodiment, the number of operating ignitions is controlled so that the first ignition plug 70A disposed substantially in the center of the combustion chamber 11 is always ignited. Preferably, the means 50a is configured so that only the second and third spark plugs 70B, 70C or only the second or third spark plugs 70B, 70C arranged on the side wall side of the combustion chamber are ignited. Since the combustion temperature in the combustion chamber 11 can be further increased than in the case, the responsiveness of the exhaust turbocharger 40 can be improved more effectively.

  As described above, the ignition control device for an internal combustion engine with an exhaust turbocharger according to the present invention is useful as a technique for improving the turbo response at the time of acceleration when the engine speed Ne is low.

1 is a diagram illustrating an example of a configuration of a first embodiment of an internal combustion engine with an exhaust turbocharger to which an ignition control device according to the present invention is applied. FIG. 1 is a bottom view of a cylinder head of an internal combustion engine with an exhaust turbocharger according to a first embodiment as viewed from a combustion chamber. It is a figure shown about the turbine pre-exhaust temperature for every engine speed at the time of full load operation in the case of 1 point ignition and the case of 2 point ignition. It is a figure shown about the turbine speed for every engine speed at the time of full load operation in the case of 1 point ignition, and the case of 2 point ignition. It is a figure which shows about the shaft torque for every engine speed at the time of full load driving | running | working in the case of 1 point ignition, and the case of 2 point ignition. 2 is an operation ignition number switching map for determining an operation ignition number according to a required torque of the internal combustion engine for each engine speed in the first embodiment. 5 is a flowchart for explaining the operation of the ignition control apparatus according to the first embodiment when the operation ignition number switching map of FIG. 4 is used. It is a figure which shows an example of a structure of Example 2 of the internal combustion engine with an exhaust turbo supercharger to which the ignition control apparatus which concerns on this invention is applied, Comprising: It is the bottom view which looked at the cylinder head of the internal combustion engine from the combustion chamber .

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 11 Combustion chamber 26 Throttle valve 27 Throttle valve actuator 40 Exhaust turbo supercharger 41 Compressor housing 42 Compressor 43 Turbine housing 44 Turbine 50A Ignition control device 50a Actuation ignition number control means 60 Fuel injection device 70A 1st ignition plug 70B 1st 2 spark plugs 70C 3rd spark plug 81 crank angle sensor 82 accelerator opening sensor

Claims (2)

In an ignition control device for an internal combustion engine with an exhaust turbocharger that controls the ignition operation of each of a plurality of spark plugs provided per cylinder,
Ignition of an internal combustion engine equipped with an exhaust turbocharger, characterized in that it is provided with an operating ignition number control means for reducing the number of ignition plugs for igniting each of the ignition plugs when accelerating at a low engine speed Control device.   The operating ignition number control means is configured to perform an ignition operation on the ignition plug disposed on the center side of the combustion chamber when reducing the number of ignition plugs that perform the ignition operation. The ignition control device for an internal combustion engine with an exhaust turbocharger according to claim 1.

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